411 REFERENCE · Wikibooks
Chess Guide for the Intermediate Player/Some basics for openings/Answer for Exercise 2
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Bxf7 WRONG Nice try, but Black can play 4. ... Kf7. You need to checkmate in 1 move! Qxe5 WRONG The e5 pawn is defended by Black Knight on c6, so he can take your Queen now! Try again! Qxf7 RIGHT That's right! Now we see a game that ends in 4 moves. So if you are playing a game, remember to keep f7 safe! We'll see more ways to defend it later. Others WRONG That isn't a check! Please look for check.